During the past 20 years, the development of the hypertext markup language (“HTML”) and web browsers has led to the creation and development of whole new industries and businesses, including Internet retailing of goods and services, search-engine services, electronic encyclopedias, direct retailing and distribution of multi-media content and software, social-networking services, and a variety of additional industries and businesses. Many businesses are based on a web site, a collection of interlinked web pages that are provided to web-site users from a web server, generally one or more servers or higher-end computer systems that receive web-page requests from users via the Internet and respond to the requests by transmitting, to requesting users, HTML files that encode web pages displayed by browser applications executing on users' computers.
The creation and maintenance of an effective web site may involve engineers and professionals of a number of different disciplines, including software engineers and web-page developers, artists, writers, and other content creators, and analysts who monitor a web site and evaluate the effectiveness of the web site on an on-going basis. As one example, an Internet retailer may spend millions of dollars in retailing web-site design and development, using teams of engineers, developers, and content creators, and may undertake continuous evaluation of retail results associated with a retailing web site, using marketing professionals and other analysts, in order to attempt to identify potential changes to the web site that can be fed back to the designers and content creators in order to optimize the web site with respect to specific goals and constraints. For an Internet retailer, the total amount of sales generated from a retailing web site, the overall number of visitors who navigate past the home page of a website, the number of redirections to allied web sites using links provided on pages of the web site, and many other metrics may comprise the goals for web-site optimization. Constraints may include human and financial resources needed to effect the changes to the web site, the time needed to make the changes, compatibility of added features with widely used browsers and browser plug-in programs, and many other such constraints.
As with any type of live or run-time testing, testing undertaken by marketing professionals and analysts may represent, to a web-site-based business or information service, large expenditures in money, time, and other resources. Furthermore, live testing may unintentionally negatively impact the web site, by creating unintended interruptions, errors, and access delays for customers. Costs and potential liabilities of web-site testing may therefore constitute a significant additional constraint for web-site optimization. For this reason, web-site developers and owners seek cost-effective, time-and-resource-economical, and minimally intrusive methods and systems for web-site testing that can provide a sound statistical basis for web-site analysis and optimization.